1. Field of the Invention
The present invention relates to modules for constructing modular bridges which are designed to be used in both a dry span role and as floating bridges.
2. Discussion of Prior Art
Where there is a requirement to transport a bridge to a particular location and construct it in a short time such as in military operations or in response to a civil disaster modular bridges comprising interconnectable modules are often used. In order to increase the versatility of such bridges they are sometimes designed to be used either in a dry span role or alternatively as floating bridges. Such a design has the added advantage that the bridge can also be used as a ferry. An example of such a bridge is referred to at page 110 of Jane's Military Vehicles and Logistics 1991. As the bridge must have sufficient flexural rigidity when used in the dry span role there is a certain amount of structural redundancy when the bridge is used as a floating bridge or ferry as the natural buoyancy of the bridge supports the majority of the weight of the bridge and any payload borne by the bridge. The consequence of this redundancy is that the weight of the bridge is unnecessarily high when the bridge is afloat and the load that the bridge can support; when afloat is accordingly reduced.